End of the line - need help salvaging relationship

Hello, I've dipped in and out of the skills over the past year. I'd be grateful for any advice or wisdom.

This is where I'm at:

We had a live-in separation last year. It lasted a few months. This is when I dove into LD, skills etc. It helped my mindset. But being a mortal woman, I slipped (he's not perfect, but that's on his paper).

We had a blow up last month caused by my disrespect. Since then we've been separated initiated by him. He has told me he is done. He considers it ended, that I need to start to move on. He hasn't missed me. Doesn't care that I'm heartbroken.

Please, any advice? I need to work on my attitude and the way I speak and treat him (I'm not terrible but there's massive room for improvement).

What can I do right now? Whenever we speak he turns the subject back to us ending. I don't want that.